/*
    * Copyright 2000-2004 The Apache Software Foundation.
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *      http://www.apache.org/licenses/LICENSE-2.0
    * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.jetspeed.modules.actions.portlets;
  
  // Java classes
  import java.io.BufferedReader;
  import java.io.FileReader;
  import java.io.IOException;
  
  import java.util.Enumeration;
  import java.util.HashMap;
  
  // Log4J classes
  import org.apache.log4j.Logger;
  import org.apache.log4j.LogManager;
  import org.apache.log4j.Appender;
  import org.apache.log4j.FileAppender;
  import org.apache.log4j.spi.LoggerRepository;
  
  // Turbine classes
  import org.apache.turbine.util.RunData;
  
  // Velocity classes
  import org.apache.velocity.context.Context;
  
  // Jetspeed classes
  import org.apache.jetspeed.portal.Portlet;
  
  /***
   * This class is the action class for a portlet that lets you view the Log4J 
   * logfiles defined in your Jetspeed installation.<br/>
   * the portlet iterates through the Log4J appender defined that are of type 
   * FileAppender or its subclasses, and lists the filenames in a listbox.<br/>
   *
   * The portlet puts the following in the context:<br/>
   * <code>appenders</code> - a HashMap with the appenders found<br/>
   * <code>files</code> - a HashMap with the filenames without path<br/>
   * <code>logfile</code> - the content of the file indicated by <code>selectedfile</code><br/>
   * 
   * 
   * @author <a href="mailto:harald@ommang.com">Harald Ommang</a>
   * @version $Id: LogfileViewerAction.java,v 1.3 2004/02/23 02:56:58 jford Exp $
   */
  public class LogfileViewerAction extends GenericMVCAction
  {
      /***
       * Static initialization of the logger for this class
       */    
       private static final Logger logger = LogManager.getLogger(LogfileViewerAction.class.getName());
  
       private static HashMap appenders = null;
  
      /*** Creates a new instance of LogFileViewerAction */
      public LogfileViewerAction() 
      {
      }
      
      /*** 
       * Lists the current logfiles
       * @param portlet The current portlet
       * @param context the current portlet context
       * @paran rundata the Turbine rundata
       *
       */
      protected void buildNormalContext(Portlet portlet, Context context, RunData rundata) throws Exception 
      {
          String tempName;
          LoggerRepository repos = logger.getLoggerRepository();
          Enumeration loggerEnum = repos.getCurrentLoggers();
          HashMap files = new HashMap();
          HashMap fileNames = new HashMap();
          appenders = new HashMap();
          
          while ( loggerEnum.hasMoreElements() )
          {
              Logger appLogger = (Logger) loggerEnum.nextElement();
              Enumeration appenderEnum = appLogger.getAllAppenders();
              String name;
  
              while ( appenderEnum.hasMoreElements() )
              {
                  Appender appender = (Appender) appenderEnum.nextElement();
                  if (appender instanceof FileAppender)
                  {
                      name = appender.getName();
                      tempName = ((FileAppender)appender).getFile();
                     tempName = tempName.substring(tempName.lastIndexOf(System.getProperty("file.separator")) + 1);
                     if (name == null)
                     {
                         name = tempName;
                         appender.setName(name);
                     }
  
                     if (logger.isDebugEnabled())
                     {
                         logger.debug("AppenderName " + name);
                     }
                     appenders.put(name, appender);
                     files.put(name, tempName);
                 }
             }
         }        
         context.put("appenders", appenders.values());
         context.put("files", files);
     }
     
     /*** 
      * If a file is selected, it's contents is put in "logfile"
      * @paran rundata the Turbine rundata
      * @param context the current portlet context
      *
      */    
     public void doUpdate(RunData data, Context context)
     {
         try 
         {        
             String fileName = data.getParameters().getString("selectedfile");
             logger.debug("selectedfile: " + fileName);
             if (fileName != null)
             {
                 String content = readFile(fileName);
                 context.put("logfile", content);
             }
             else
             {
                 context.put("logfile", null);
             }
         }
         catch (Exception ex)
         {
             logger.error("Exception in viewing logfile: ", ex);
         }
     }
 
     /*** 
      * Reads the contents of a file and returns in \n separated lines.
      * @paran filename Name of file to read
      *
      */        
     private String readFile (String filename) 
     {
         StringBuffer buf = new StringBuffer("");
         try 
         {
             String line;
             BufferedReader in = new BufferedReader(new FileReader(filename));
             while ((line = in.readLine()) != null) 
             {
                 buf.append(line + "\n");
             }
             in.close();
         } 
         catch (IOException ioe) 
         {
             logger.error("Error reading file " + filename, ioe);
         }
         return buf.toString();
     } // readFile
     
 } // class LogfileViewerAction